Charles m



(N o Mod e i.) I '2 Shets-Sheet 1.

D. 'H; RICE, Deod. G. M. WILLIAMS, W. R. CHESTER & L. H. RICE, Executors.

ELECTRIC CALLING APPARATUS.

No. 517,299. Patented Mar. 27, 18

(No Model.) A 2 Sheets-Sheet 2.

. D. H: RICE, Decd. C. M. WILLIAMS, W. R. CHESTER & L. H. RICE, Executors.

ELECTRIC CALLING APPARATUS.

Patented Mar. 27, 1894.

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I UNITED STATES PATENT OFFICE DAVID HALL RICE, OF BROOKLINE, MASSACHUSETTS; CHARLES M. WILLIAMS, OF LOWELL, MASSACHUSETTS, AND WALSTEIN R. CHESTER AND LEPINE HALL RICE, EXECUTORS OF SAID DAVID HALL RICE, DECEASED.

ELECTRIC CALLING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 517,299, dated March 2'7, 1894. Application filedFebruary 11, 1892. Serial No. 421,139- (No model.)

To all whom it may concern.-

Be it known that I, DAVID HALL RICE, of Brookline, in the county of Norfolk and State of Massachusetts, have invented a new and useful Improvement in Electric Calling Apparatus, of which the following is a specification.

My invention relates to apparatus for calling or alarming at different stations on the same electric circuit, and it consists in certain new and useful combinations and constructions thereof, substantially as hereinafter described and claimed. Y

In the drawings my invention is shown as applied to the well known Currier bell system, an example of an application of which is shown in the Letters Patent No. 307,494,

granted to me November 4, 1884.

Figure 1 shows the calling apparatus located at a central station, and the alarm apparatus located at two subscribers stations on an electric circuit, with the adjuncts necessary to carry out the invention. Fig. 2 is an elevation of part of the mechanism at a station on the electric circuit, showing an improved form of automatic governor for the secondary circuit. Fig. 3 is an elevation of part of Fig. 2 showing a modification in the details of construction. Fig. 4 is a side elevation of part of Fig. 2, showing the mode of attaching the governor magnet to its backboard.

The so-called Currier bell system operates its several bells at the subscribers stations by intermittent currents of electricity, adjusted to different rates of pulsation to which the alarm hammers are respectively adjusted, so that no one vibratory current will ring the alarm at a different station from that, with the vibrating striker of which it is in isochronous adjustment. It requires, when all its alarm striker magnets at the different stations are directly in the same circuit, that a fairly constant electric current shall be employed strongenough to setthe vibrating strikers in action with reasonable quickness and yet not so strong as to pull the striker against the alarm bell, or other sounder, with the first impulse of the electric current. If the latter 50 occurs the synchronous action of the several strikers at the difierent stations is destroyed, and the alarms of all the stations are sounded. This destroys the special utility of the bell by destroying its individual character. Again,

in sending an electric current over a circuit which passes through all the alarm magnets, the electricity must necessarily be of high tension to be certain of traversing the circuit to distant stations, while when it reaches the stations it does not do as effective work in pulling upon the bell hammer and sounding the alarm as if it was of lower tension and greater volume. By my present invention these difficulties are overcome, and I am able to employ a source of electricity of wider variation, as well as to obtain more efficient work from the electric current used.

A is a central station equipped with acalling apparatus, V, small magneto or dynamo machine M and switch S. The circuit, 1, leads from the ground, G, through the dynamo M, magnet 12, vibrator w, and bow spring, 0 to the contact, 8', of the switch. The circuit, 2, branches off from it just beyond the dynamo and leads through the magnet c vibrator w 7 5 bow spring 0 to the contact 8 of the switch.

A shunt, g, used in telephone service leads around the caller from the contact, g, of the switch to the ground G. The vibrator 12 is adjusted to give a different rate of vibrations, when set in motion, from that of vibrator 10. Each vibrators wings its bow spring, 0 or 9 past its contact (1 or (1 from which the 011:- cuit leads to the switch, and thus automatically breaks its own circuit and keeps itself in vibration at the rate at which it is adjusted. The switch S is provided with the swinging metallic arm, a, adapted to be swung over and make contact with either of the metal contact points, 5 or and so put the or: desired vibrator into circuit. From the pivot of the arm, a, the line circuit, 3, leads to the several subscribers stations and thence to the ground G. I

Thus far the apparatus is the same as here- 5 tofore used, but instead of carrying the circuit, 3, directly through the alarm striker magnet at station, A, I make it the primary circuit of the converter, 0', which is arranged to convert a part of the high tension current 10) of circuit, 3, into a current of lower tension and greater volume by induction. The converter 0 consists of a number of soft iron rings or disks laid together side by side and insulated from each other, if desired, by shellac or paper. Around these the circuit, 3, is wound the requisite number of turns. The secondary circuit of larger wire, 11, is also wound around the core of converter 0' the proper number of times to take off the desired amount of current. It is then made to pass through the electric governor, R, by way of its magnet, the guide rod, p, armature a, and supporting contact post a Thence the circuit, 11, is carried through the alarm magnet, m', and back to the converter. The armature, h, of this magnet is also the bell hammer of bell, B, and it is adjusted so as to vibrate isochronously with the vibrator, .w, of the caller.

The arrangement of the various parts at station, A, is the same as at station A, except that its alarm striker, h, is adjusted to vibrate isochronously with vibrator, w, of the caller, and a somewhat different size of wire is used for the secondary circuit of the converter, 0 to adapt the amount of current taken off of it to the different tension of spring used in the vibrator w As the stilfness or tension of the vibrator springs vary to give the difierent rate of vibration desired, a different amount of current is desirable to operate each one. This may be obtained by a difference in winding the primary or secondary coil on each converter instead of by varying the sizes of the secondary circuit wire.

The governor illustrated is the one set forth in the applications of J. B. Currier, Serial No. 47,978, filed December 15, 1881, and of said Currier and applicant, No. 78,141, filed December 1, 1882. It consists of the magnet, R, with itself and its armature, a, in circuit and held by gravity upon the point of the metallic pin, a. If the current becomes too strong for the alarm the magnet R slightly lifts bar, a, and interposing an air bridge weakens it as desired. The rod, 12, is attached to bar, a, and forms the guide piston to cause it to lift and drop back vertically. The contact pin, a is intended to be supported upon the wooden back-board of the governor, which supports the parts of the same in their relative position to each other. The bar a is of soft iron. The striker, 72. is adjusted to vibrate in unison with its circuit breaker at the central station by lengthening or shortening its spring in its holding clamp in the usual way.

Although I show the foregoing well-known automatic governor, yet the one I prefer differs in material points from it, which I have devised to better control the secondary circuit current. This new governor is based upon the fact that if the converter ring core be cut open and a piece of metal be fitted to fill the opening, the current of the secondary circuit may be varied by moving this piece of metal into or out of place.

In Fig. 2 the converter core is formed of the insulated thin rings of soft iron, 0 ,0 0 c, 0 Pieces are cut out of these at the top of the core in the general shape of a wedge, and the pieces of soft iron, a ,a a, a, 0. are accurately fitted to the opening and fastened together by the pin, 19, and nut 19 On this pin is also attached by brazing or soldering the soft iron armature, a, of the magnet, R, which is in the secondary circuit 11. The pin, 19, extends loosely through the top bar of the magnet and serves as a guide rod to the armature when it rises and falls. The, magnet R is attached to the wooden backboard, r, by a plate attached to its top bar, through slots 4*, W, of which the screws r, r', pass, so that it may be adjusted nearer to or farther away from the armature a. The bell, B and its magnet, m, is in the secondary circuit. When the current of the secondary circuit exceeds a certain strength, it lifts the armature, a), and wedge piece which completes the annular core and immediately weakens itself, when the wedge piece will drop back or remain suspended for a longer or shorter period.

In Fig. 3 is shown a modification of the governor shown in Fig. 2. The metal pieces a, a, a, a, a, which severally complete the annular layers of metal o 0 0 0 c, instead of being secured closely on the lower end of pin 1), with insulation between them as in Fig. 2, are mounted loosely on the pin in such position that when the pin and its armature, a, drop down they will complete said annular metal layers as shown, and have slight spaces between them. When the armature and pimp, is lifted by the magnet, R, as in Fig. 2, the nut, p comes against the lower filling piece, a, and lifts that first, and as it rises, it in turn lifts piece, or, and the two continuing to rise lift piece, a, and so on until all the pieces are lifted out. This operation weakens the current in the secondary circuit, 11, more gradually than the construction of Fig. 2 and is preferable in that respect.

The various parts of the alarm device at station, A are the same as at station, A, except that the spring of the bell hammer and armature, h, is adjusted so that it will vibrate isochronously with its circuit-breaker, tu at the central station. This rate of vibration is made to diifer widely enough from that of the alarm of station, A, to prevent both bells from being struck by the vibration of the same circuit-breaker.

To operate the apparatus the switch arm, a, at the central station is placed upon the proper contact point, as for example 8, and the handle of the dynamo Mis turned to produce the current. This sets in operation the circuit-breaker, w, which sends a pulsatory current over the line 3, which is taken 06 onto the line, 11, by induction at the con- IIO verter, O, and rings bell B. The same current taken off by induction by converter, 0 will not ring the bell at that station on account of its different rate of vibration from that of the bell hammer there.

Care should be taken to wind the governor magnet and bell magnet at each station with wire large enough to correspond with the secondary circuit in which its bell is placed. The alarm hammers may be made to sound an alarm upon some other object, instead of a bell, if desired and still be within myinvention.

What I claim as new and of my invention 1s 1. The combination of an electric circuit containing a source of electric energy, two circuit-breakers arranged to send pulsatory or broken currents of different predetermined rates of vibration over said circuit, two converters placed in said circuit, each arranged to take off part of the current passing over it by induction, and each having a secondary circuit containing in it a magnet with its armature arranged to vibrate isochronously with one of said circuit breakers and not with or in response to the other, substantially as described.

2. The combination of an electric circuit, a source of electrical energy included therein, two circuit-breakers arranged to send pulsatory or broken currents of different predetermined rates of vibration over said circuit, two converters placed in said circuit arranged respectively to take off different proportions of the current passing over it by induction, and having respectively secondary circuits and magnets included in them with their armatures suspended on springs of difierent degrees of tension, corresponding to the dinerent proportions of current taken off by their respective converters, and arranged to be vibrated by said circuit-breakers and sound an alarm, substantially as described.

3. The combination of an electric circuit, a source of electrical energy included therein, two circuit-breakers respectively arranged to send pulsatory or broken currents of different predetermined rates of vibration over said core, an armature'connected with said block,

and a magnet in the secondary circuit of said converter, arranged to lift said armature and withdraw said block, when the electric current generated by said converter exceeds a predetermined strength, substantially as described.

5. The combination of the converter provided with an annular core formed of insulated layers of soft iron having a segment cut out of them on one side, and a metal block formed of independent pieces of metal attached independently to a support, each arranged to fill the place cutout of the corresponding layer of the core, and to be lifted out from the same independently of and successively to the others, whereby the current in the secondary circuit will be gradually weakened, substantially as described.

6. The combination of a converter provided with an annular core formed of independent layers of soft iron, having a segment cut out of them on one side, a series of pieces of metal attached to an armature and arranged to be lifted successively thereby and to fill the places cut out of the corresponding layers of the core, and a magnet in the secondary circuit of the converter, arranged to lift said armature and attached metal pieces, when the strength of the electric current in said secondary circuit exceeds a predetermined amount,

substantially as described.

DAVID HALL RICE. Witnesses:

B. O. MOULTON, N. P. OOKINGTON. 

